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      1 ; Test that the memcmp library call simplifier works correctly.
      2 ;
      3 ; RUN: opt < %s -instcombine -S | FileCheck %s
      4 
      5 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128-n8:16:32:64"
      6 
      7 @foo = constant [4 x i8] c"foo\00"
      8 @hel = constant [4 x i8] c"hel\00"
      9 @hello_u = constant [8 x i8] c"hello_u\00"
     10 
     11 declare i32 @memcmp(i8*, i8*, i32)
     12 
     13 ; Check memcmp(mem, mem, size) -> 0.
     14 
     15 define i32 @test_simplify1(i8* %mem, i32 %size) {
     16 ; CHECK-LABEL: @test_simplify1(
     17   %ret = call i32 @memcmp(i8* %mem, i8* %mem, i32 %size)
     18   ret i32 %ret
     19 ; CHECK: ret i32 0
     20 }
     21 
     22 ; Check memcmp(mem1, mem2, 0) -> 0.
     23 
     24 define i32 @test_simplify2(i8* %mem1, i8* %mem2) {
     25 ; CHECK-LABEL: @test_simplify2(
     26   %ret = call i32 @memcmp(i8* %mem1, i8* %mem2, i32 0)
     27   ret i32 %ret
     28 ; CHECK: ret i32 0
     29 }
     30 
     31 ;; Check memcmp(mem1, mem2, 1) -> *(unsigned char*)mem1 - *(unsigned char*)mem2.
     32 
     33 define i32 @test_simplify3(i8* %mem1, i8* %mem2) {
     34 ; CHECK-LABEL: @test_simplify3(
     35   %ret = call i32 @memcmp(i8* %mem1, i8* %mem2, i32 1)
     36 ; CHECK: [[LOAD1:%[a-z]+]] = load i8, i8* %mem1, align 1
     37 ; CHECK: [[ZEXT1:%[a-z]+]] = zext i8 [[LOAD1]] to i32
     38 ; CHECK: [[LOAD2:%[a-z]+]] = load i8, i8* %mem2, align 1
     39 ; CHECK: [[ZEXT2:%[a-z]+]] = zext i8 [[LOAD2]] to i32
     40 ; CHECK: [[RET:%[a-z]+]] = sub nsw i32 [[ZEXT1]], [[ZEXT2]]
     41   ret i32 %ret
     42 ; CHECK: ret i32 [[RET]]
     43 }
     44 
     45 ; Check memcmp(mem1, mem2, size) -> cnst, where all arguments are constants.
     46 
     47 define i32 @test_simplify4() {
     48 ; CHECK-LABEL: @test_simplify4(
     49   %mem1 = getelementptr [4 x i8], [4 x i8]* @hel, i32 0, i32 0
     50   %mem2 = getelementptr [8 x i8], [8 x i8]* @hello_u, i32 0, i32 0
     51   %ret = call i32 @memcmp(i8* %mem1, i8* %mem2, i32 3)
     52   ret i32 %ret
     53 ; CHECK: ret i32 0
     54 }
     55 
     56 define i32 @test_simplify5() {
     57 ; CHECK-LABEL: @test_simplify5(
     58   %mem1 = getelementptr [4 x i8], [4 x i8]* @hel, i32 0, i32 0
     59   %mem2 = getelementptr [4 x i8], [4 x i8]* @foo, i32 0, i32 0
     60   %ret = call i32 @memcmp(i8* %mem1, i8* %mem2, i32 3)
     61   ret i32 %ret
     62 ; CHECK: ret i32 1
     63 }
     64 
     65 define i32 @test_simplify6() {
     66 ; CHECK-LABEL: @test_simplify6(
     67   %mem1 = getelementptr [4 x i8], [4 x i8]* @foo, i32 0, i32 0
     68   %mem2 = getelementptr [4 x i8], [4 x i8]* @hel, i32 0, i32 0
     69   %ret = call i32 @memcmp(i8* %mem1, i8* %mem2, i32 3)
     70   ret i32 %ret
     71 ; CHECK: ret i32 -1
     72 }
     73 
     74 ; Check memcmp(mem1, mem2, 8)==0 -> *(int64_t*)mem1 == *(int64_t*)mem2
     75 
     76 define i1 @test_simplify7(i64 %x, i64 %y) {
     77 ; CHECK-LABEL: @test_simplify7(
     78   %x.addr = alloca i64, align 8
     79   %y.addr = alloca i64, align 8
     80   store i64 %x, i64* %x.addr, align 8
     81   store i64 %y, i64* %y.addr, align 8
     82   %xptr = bitcast i64* %x.addr to i8*
     83   %yptr = bitcast i64* %y.addr to i8*
     84   %call = call i32 @memcmp(i8* %xptr, i8* %yptr, i32 8)
     85   %cmp = icmp eq i32 %call, 0
     86   ret i1 %cmp
     87 ; CHECK: %cmp = icmp eq i64 %x, %y
     88 ; CHECK: ret i1 %cmp
     89 }
     90 
     91 ; Check memcmp(mem1, mem2, 4)==0 -> *(int32_t*)mem1 == *(int32_t*)mem2
     92 
     93 define i1 @test_simplify8(i32 %x, i32 %y) {
     94 ; CHECK-LABEL: @test_simplify8(
     95   %x.addr = alloca i32, align 4
     96   %y.addr = alloca i32, align 4
     97   store i32 %x, i32* %x.addr, align 4
     98   store i32 %y, i32* %y.addr, align 4
     99   %xptr = bitcast i32* %x.addr to i8*
    100   %yptr = bitcast i32* %y.addr to i8*
    101   %call = call i32 @memcmp(i8* %xptr, i8* %yptr, i32 4)
    102   %cmp = icmp eq i32 %call, 0
    103   ret i1 %cmp
    104 ; CHECK: %cmp = icmp eq i32 %x, %y
    105 ; CHECK: ret i1 %cmp
    106 }
    107 
    108 ; Check memcmp(mem1, mem2, 2)==0 -> *(int16_t*)mem1 == *(int16_t*)mem2
    109 
    110 define i1 @test_simplify9(i16 %x, i16 %y) {
    111 ; CHECK-LABEL: @test_simplify9(
    112   %x.addr = alloca i16, align 2
    113   %y.addr = alloca i16, align 2
    114   store i16 %x, i16* %x.addr, align 2
    115   store i16 %y, i16* %y.addr, align 2
    116   %xptr = bitcast i16* %x.addr to i8*
    117   %yptr = bitcast i16* %y.addr to i8*
    118   %call = call i32 @memcmp(i8* %xptr, i8* %yptr, i32 2)
    119   %cmp = icmp eq i32 %call, 0
    120   ret i1 %cmp
    121 ; CHECK: %cmp = icmp eq i16 %x, %y
    122 ; CHECK: ret i1 %cmp
    123 }
    124